Axial Gravitational Perturbations of Slowly-Rotating Compact Objects in General Relativity and Beyond

TL;DR

This paper derives a simplified master wave equation for axial gravitational perturbations of slowly-rotating compact objects supported by anisotropic fluids, facilitating easier calculations of gravitational quasinormal modes in general relativity and beyond.

Contribution

It introduces a decoupled master wave equation for axial perturbations of rotating compact objects, streamlining the computation of gravitational quasinormal modes.

Findings

Decoupling of gravitational and matter perturbations in axial sectors.

Derivation of a master wave equation with a metric-determined potential.

Simplified calculation method for gravitational QNMs in specific backgrounds.

Abstract

We study the axial gravitational perturbations of slowly-rotating compact objects which are assumed to be supported by anisotropic fluids. We find that the gravitational perturbations decouple from the matter perturbations for axial sectors. We obtain a master wave equation whose potential is fully determined by the metric functions. This equation makes the calculations of gravitational QNMs for rotating compact objects extremely easy in specific background configurations.